John Milton, The History of Britain, that Part Especially Now Call'd England: From the First Traditional Beginning, Continu'd to the Norman Conquest, 2nd ed. (London, 1677).
This is a posthumous, second edition of Milton's The History of Britain first published in 1670. As the subtitle shows, the volume covers from the beginning of the British history to the Norman Conquest; large part of it deals with the Anglo-Saxon period.
Milton wrote it much earlier than it was published; the first four books in the 1640s, and the remaining two books in the 1650s. In the Defensio Secunda (1654), Milton writes that he was intending to write a history up to his own age, and so this volume may well have originally been intended as just the beginning of a much bigger project. In the same work, he also writes that he was composing the History as a private exercise. This may well be a reason why it was not published long after it was written; it was just a beginning part of a longer history and anyway it was originally intended as a private thing.
As he was serving for the Commonwealth and was publishing political tracts defending the Parliament and the Commonwealth government, and also justifying King Charles I's execution, he hided himself after the Restoration in 1660. When he emerged from hiding, he was arrested and imprisoned in the Tower of London for some time but he was eventually released. Milton was in disfavour with the new government, and did not (or could not) publish anything for more than six years until 1667, when his Paradise Lost was published. This gives another good reason for the History not to have been published long after it was originally composed.
As Graham Parry points out, it is likely that Milton added the following last paragraph of the volume as his 'muted comment on the Restoration scene' (Parry, 'Introduction', p. 46):
If these were the Causes of such Misery and Thraldom to those our Ancestors, with what better close can be Concluded, than here in fit season to remember this Age in the midst of her Security, to fear from like Vice without amendment the Revolution of like Calamities. (p. 357)
Due to the Norman Conquest, which is the last major topic of the volume, the English people forced into submission to the Norman yoke. Milton may have compared the situation after the Norman Conquest with that in his own time when Milton might have considered, the English people were once again subjugated to the royal supremacy and oppressive aristocratic establishment after the Restoration.
Milton extensively uses Æthelweard's Chronicle, along with major medieval histories such as those by Gildas, Bede, William of Malmesbury, Henry of Huntingdon, Symeon of Durham, et al, which is impressive, since Æthelweard's Chronicle is never used by medieval historians other than William of Malmesbury, who is the last 'witness' of it before scholars started to mention it again in the sixteenth century. Henry Savile published its editio princeps in 1596, and probably Milton used it, since there was only one manuscript recording Æthelweard's Chronicle, British Library, Cotton Otho A.x, which was mostly destroyed in the fire in 1731.
My copy was once owned by D. P. Alford, vicar of Tavistock, who left sporadic neat inscriptions.
A facsimile of the second edition of this book is published as John Milton, The History of Britain: A Facsimile Edition with a Critical Introduction by Graham Parry (Stamford: Paul Watkins, 1991).
For more details about Milton's History of Britain, see Graham Parry, 'Introduction', in the aforementioned facsimile edition, pp. 7-48.